📐 Pipe Support Span (ASME B31)

Determine maximum allowable pipe span and support spacing based on sag deflection limits (2.5 mm) and ASME B31 allowable bending stress.

⚡ Fortran 90 Engine Double Precision (IEEE 754) ✓ ISO / ASME Validated

Process

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⚡ Solves 25

💾 Downloads 258 📦 Fortran Code 4.4 KB

📅 Released Jun 2026

⏱️ Latency < 1 ms

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📐 Multi-Span Continuous Pipe Deflection & Support Stanchions

Real-time visual simulation of elastic beam sag under gravity & insulation weight

📝 Configuration & Presets

💧 6" Water Line (Sch 40) ♨️ 10" Insulated Steam (300°C) 🛢️ 4" Fuel Oil Line 💨 16" Gas Header

📏 Pipe Geometry & Elasticity

Outside Diameter D_o [mm]:

Wall Thickness t [mm]:

Modulus of Elasticity E [GPa]: Carbon Steel: 200 GPa, Stainless: 190 GPa

Hot Allowable Stress S_h [MPa]: ASME B31 allowable (e.g. 138 MPa)

🧪 Fluid Content & Thermal Insulation

Fluid Density ρ_fluid [kg/m³]: Water: 1000, Gas: 0–50, Oil: 850

Insulation Thickness [mm]:

Insulation Density [kg/m³]: Mineral wool / Calcium silicate: ~140 kg/m³

Allowable Sag Deflection [mm]: Standard limit: 2.54 mm (0.1 in) or L/360

ASME B31 Span Formulations:
• Total Weight: w = w_pipe + w_fluid + w_ins [N/m]
• Deflection Limit: L_δ = [ (384 E I δ_allow) / (5 w) ]^¼
• Stress Limit: L_σ = √[ (8 Z S_allow) / w ], with S_allow ≤ 0.23 S_h
• Maximum Allowable Span: L_max = min(L_δ, L_σ)

📊 Pipe Span Results

📊 Output Summary
💾 Fortran Source

Recommended Maximum Support Spacing

L_max = 5.59 meters (18.4 ft)

Governing Criterion: Deflection Limit (Sag ≤ 2.5 mm)

w = 459.7 N/m

Deflection-Limited Span (L_δ) 5.59 m Sag Limit = 2.5 mm

Stress-Limited Span (L_σ) 8.77 m S_allow = 31.7 MPa

Pipe Steel Linear Weight 277.2 N/m 28.3 kg/m

Fluid + Insulation Weight 182.5 N/m Fluid = 182.5 N/m, Ins = 0.0 N/m

📈 Maximum Allowable Span vs Standard Pipe Size (NPS)

📉 Midspan Sag Deflection vs Support Spacing

=================================================================
 THERMOFLUIDCALC — ASME B31.1 / B31.3 PIPE SPAN REPORT
=================================================================
Case Title                 : 6" Water Utility Distribution Line (Sch 40)
Outside Diameter (Do)      : 168.30 mm
Wall Thickness (t)         : 7.11 mm
Elastic Modulus (E)        : 200.0 GPa
Material Allowable Sh      : 138.0 MPa
Total Distributed Weight   : 459.66 N/m (46.86 kg/m)
-----------------------------------------------------------------
Deflection-Limited Span    : 5.59 meters (18.35 ft)
Stress-Limited Span        : 8.77 meters (28.77 ft)
RECOMMENDED MAXIMUM SPAN   : 5.59 meters (18.35 ft)
Governing Criterion        : Deflection Limit (Sag ≤ 2.5 mm)
=================================================================

📘 Calculation Methodology & ASME Standards

Deflection Limit Criterion

To prevent liquid pocketing, condensate pooling, and excessive slope distortions in drainage lines, sag is restricted to $2.54\,\text{mm}$ ($0.1\,\text{in}$):

                    Lδ = [ (384 E I δallow) / (5 w) ]¼
                

ASME B31 Sustained Bending Stress

Weight bending stress is allocated a budget $S_b \le 0.23 S_h$ to preserve allowable stress margin for internal pressure and thermal expansion.

Key Engineering Assumptions

Uniform continuous multi-span beam behavior with simple supports.
Combined weight includes pipe steel, fluid contents, and insulation jacket.
No concentrated heavy valves at midpoint (if present, span should be reduced by 30–40%).

ThermoFluidCalc Engineering Report